Suggested for use in cars and motorcycles, this circuit was found in a 90s Popular Electronics. The MOSFET can be anyone that supports the current of the lamps. Adaptations can be made to use LEDs.
This circuit was found in Electronics Handbook, Vol XIII 1993 and consists of a simple direction...
This circuit works only with carbon microphones, due its low impedance. The speaker should be good or...
This is the normal circuit of a relaxation oscillator using an unijunction transistor such as the...